In using conventional laryngoscopes, it is only by trial and error that the blade of the laryngoscope can be inserted into the pharynx in such a manner to elevate the epiglottis so that an endotracheal tube can be manually moved into the throat and into the larynx. This is because the larynx cannot always be directly and completely viewed during insertion of the blade. Usually, the laryngoscope is held in one hand as the endotracheal tube is held in the other hand because the laryngoscope has no means for both removably holding and guiding the endotracheal tube. This is an awkward situation because the user of the laryngoscope must be able to probe the pharynx without actually seeing the epiglottis in an attempt to elevate it yet the user must be ready to insert the tube as soon as the epiglottis is elevated. Most importantly, the line of sight from the eye of the anesthesiologist to the epiglottis and larynx must be straight using direct vision; whereas, the endotracheal tube must frequently be passed in a curved manner to conform with the normal anatomical pharyngeal curvature. The anesthesiologist, in these cases, is therefore asked to straighten out the normal physiological curve of the pharynx. This may result in damage to the patient's teeth, and "soft parts." Thus, considerable time and effort is expended in elevating the epiglottis and then inserting the tube, all of which must be done while causing only a minimum amount of discomfort to the patient.
The insertion of a conventional laryngoscope in the throat is a very tedious process in many cases and in some cases, injury is caused to the patient by virtue of the movements of the laryngoscope blade within the narrow confines of the physiological limitations of the patient. No satisfactory laryngoscope has been heretofore provided for effectively guiding the endotracheal tube into the throat while providing for the direct and indirect viewing of the throat during the insertion of the blade to elevate the epiglottis.
Representative laryngoscopes are disclosed in the following U.S. Pat. Nos. 2,646,036, 3,986,854 and 4,086,919. An endoscope which is related to a laryngoscope is disclosed in U.S. Pat. No. 3,896,793. The laryngoscopes of these references do not provide for the guiding of an endotracheal tube while permitting direct and indirect viewing of the throat during insertion of the blade of the laryngoscope. Moreover, there is no teaching or suggestion in these references that the blade can be shaped to fit different physiological throat configurations of various patients nor do the references suggest the need for improvements in laryngoscope blades.
Because of the shortcomings of conventional laryngoscopes as mentioned above, a need has arisen for improvements in laryngoscopes which facilitate the elevating of the epiglottis and the insertion of an endotracheal tube into the throat to minimize the discomfort to a patient.